A cross-sectional study of individuals seeking information on transient ischemic attack and stroke symptoms online: a target for intervention?

1Department of Neurology, University of California San Francisco, San Francisco, California, USA. akim@ucsf.edu

Abstract

BACKGROUND:

Individuals with TIA/stroke symptoms often do not seek urgent medical attention. We assessed the feasibility of identifying individuals searching for information on TIA/stroke symptoms online as a target for future interventions to encourage urgent evaluation and we evaluated the performance of a self-reported risk score to identify subjects with true TIA or stroke.

METHODOLOGY/PRINCIPAL FINDINGS:

We placed online advertisements to target English-speaking adults in the United States searching for TIA/stroke-related keywords. After completing an online questionnaire, participants were telephoned by a vascular neurologist to assess the likelihood of TIA/stroke. We used logistic regression and the c-statistic to assess associations and model discrimination respectively. Over 122 days, 251 (1%) of 25,292 website visitors completed the online questionnaire and 175 were reached by telephone (mean age 58.5 years; 63% women) for follow-up. Of these participants, 37 (21%) had symptoms within 24 hours, 60 (34%) had not had a medical evaluation yet, and 68 (39%) had TIA/stroke. Applying a modified ABCD(2) score yielded a c-statistic of 0.66, but 2 of 12 with a zero score had a TIA/stroke. Those with new symptoms were more likely to have TIA/stroke (OR 4.90, 95% CI 2.56-9.09).

CONCLUSIONS/SIGNIFICANCE:

Individuals with TIA/stroke that are seeking real-time information on symptoms online can be readily identified, in some cases before they have sought formal medical evaluation. Although a simple self-reported risk score was unable to identify a low-risk population in this selected group, this population may still present an attractive target for future interventions designed to encourage urgent medical evaluation.

Percent of participants with transient ischemic attack or stroke by self-reported ABCD2 score.

A modified ABCD2 score was calculated from self-reported components of the score (age > = 60 = 1 point; Clinical Features: Speech Disturbance without weakness = 1 point, Unilateral Weakness = 2 points; Duration: 10–59 minutes = 1 point, >60 minutes = 2 points; Diabetes = 1 point). The blood pressure item was excluded since this was not likely to be available by self-report, so the range of this risk score was 0 to 6. The grey bars show the proportion observed and the black vertical lines represent the 95% confidence interval around that proportion. The one enrollee with a score of 6 had migraine.